1. Field of the Invention
This invention relates to simulation tools, and more particularly to a tool for simulating a wireless environment for a multiuser subscriber communication system.
2. Background
Wireless communication devices (WCDs) are becoming increasingly commonplace. For example, millions (if not billions) of individuals own and/or utilize one or more WCDs such as, but not limited to, a mobile phone, personal data assistant (PDA), a wireless gaming device and a computer with wireless capabilities. To support the growing numbers of WCDs, there are also many numbers of service providers. A user subscribes with one of these service providers to receive service.
Each carrier forms a network that provides wireless service to its subscribers in various geographical areas of the world. For example, one service provider may provide service covering the East Coast region of the United States while another may provide service covering various portions across the United States. In order to provide wider geographical service to the subscribers, two or more service providers (hereinafter roaming partners) may form agreements that allow subscribers of one network to access other networks.
Thus, when a subscriber enters a region that is not directly covered by its carrier, but is covered through an agreement, the WCD of the subscriber is said to be “roaming.” A WCD in a roaming mode scans for and selects a network to provide service to the WCD. Depending on agreements, if any, and/or policies, each service provider has a roaming list that assists a WCD in acquiring service. The roaming list is an indexed list of systems or networks that is stored in each WCD and may be proprietary. Additionally, a set of data structures and algorithms, for service selection identifies the best network suitable for a given WCD to operate in a given environment.
The roaming list can be any listing compatible with the communication standard used by the WCD. Examples of roaming lists are a public land mobile network list (PLMN list) and a Preferred Roaming List (PRL). The set of data structures and algorithms may be called system determination (SD) and can be used in combination with the roaming list to provide the identification of the best network suitable for the operation of a given WCD. While the terminology “PRL” and “system determination” are used herein, it is understood that the concepts are applicable to a variety of standards and technologies used in connection with wireless networks and wireless subscriber networks.
As applied to roaming, a Technical Data Sheet (TDS) is a document exchanged by roaming partners as a listing of available services to convey changes and additions to the network elements. It may contain information such as, but not limited to, the Home Location Resource (HLR), switches, SIDs, channel information and contact information. The TDS is used to help create the PRL, but is not standardized and exists in different formats.
The system determination procedure uses the PRL in the WCD to select a system that will provide service to the WCD. This selection process is not standardized. Also, the system determination is dependent on the OEM's implementation and may be proprietary. Accordingly, service providers may have no specific insight on how a particular system was selected. Therefore, it can be difficult for service providers to troubleshoot PRL problems. On the other hand, due to the proprietary nature of PRLs, it may be difficult for OEM to help troubleshoot the PRL problem. For example, a representative of OEM can manually examine the PRL and step through it's contents, while making assumptions on how the PRL is being executed in the service provider's environment. Therefore, there is a need to provide information that is useful to the service providers without compromising the proprietary information.